Anyone run a catch can to the exhaust?

[BoostedSVT03]

I wonder if you could use a UPR style catch can where the inlets are on the sides and the outlet is on top. You could then return it back to the intake.

 

[s351]

Is the vibrant performance evac scavenging kit a viable option? Does it actually pull vac at idle?

 

[ctgreddy]

What we've done at work with cars that have this issue is essentially take the filter off the top of the can, and run a hose to the air filter. Either cut a hole in the front of the filter and put the hose in it or slant cut the hose and put it as close to the filter as possible. Most of it is just vapor so you wont get an oil build up in the intake it'll just suck up the smell. It's helped a lot.

 

[stradt03]

Malcom, do you have a video showing the vapor that you are getting out of the cans at idle? I'd like to compare it to mine.

 

[MalcolmV8]

Malcom, do you have a video showing the vapor that you are getting out of the cans at idle? I'd like to compare it to mine.

I don't.

 

[TRBO VNM]

I have the same issue with my direct injection BMW. Oily vapors build up on the back of the intake valves and need to be walnut blasted every 30 to 50k miles. Guys have tried all sorts of fancy catch cans to eliminate it and at best all they can do is slow it down.

That is what we are fighting with the ST's. But we are all running them back to the intake like you mention and still do get some oil past the can. I just checked my valves an there is some minor build up, but not bad. The solution, not cheap, but those of us going "big turbo" are using auxiliary fuel where the injectors spray on the valves. This will keep them clean.

 

[MalcolmV8]

That is what we are fighting with the ST's. But we are all running them back to the intake like you mention and still do get some oil past the can. I just checked my valves an there is some minor build up, but not bad. The solution, not cheap, but those of us going "big turbo" are using auxiliary fuel where the injectors spray on the valves. This will keep them clean.

Same with the BMWs, there is no aftermarket, mechanical, engine driven high pressure pump available for the DI so you have to add auxiliary injectors to get around it. I have the boost turned up and limited to around 5 gallons of E85 in the tank for about an E55 mixture so I don't exceed the fuel system. It's just a daily so not bothered with adding injectors etc. My point is catch cans don't eliminate oil as a lot of people seem to think. They do catch some and slow it down but there's still oil getting by which is why mine won't go to the intake.

I'm collecting various parts now to build something custom to the exhaust and hopefully in about a week or so we'll see how it does.

 

[65fastback289]

My car has a bit more blow by than a stock motor due to larger ring gaps for higher boost. The catch cans tend to steam / smoke more than I'd like and it's annoying at times and of course catch cans stink. E85 makes it much nicer but still gets old.

Thinking about removing the filters off the top of the catch cans (which are hidden inside the fender wells) and running a hose to the X pipe so the exhaust scavenges out the smells and puffs of smoke at times. I'd have to go to almost the end of the X into the cat back to be past my wideband sensor as to not mess that up. Been a dual 3" I don't know if there'll be much exhaust velocity at that point to create a suction but should still work. The exhaust should still be hot enough at that point to burn off any steam or mild smoke. When I say smoke it's very faint and fine, you almost think your eyes are playing tricks on you seeing it.

Anyone done something like this? Any feedback?

I have this done on the Cobra and I also run e85. Except, I don't have catch cans and have 2 hoses that run to the x pipe. The biggest thing I noticed was not having a mess and the steam/smoke in the engine bay. Nor did I notice anything extra from the rear of the car.

 

[MalcolmV8]

I have this done on the Cobra and I also run e85. Except, I don't have catch cans and have 2 hoses that run to the x pipe. The biggest thing I noticed was not having a mess and the steam/smoke in the engine bay. Nor did I notice anything extra from the rear of the car.

Very cool. I probably could have skipped the driver's side catch can as it only seems to collect moisture that stinks like E85. Passenger's side collects the same moisture with a small layer of oil on top. Even that probably would have burned OK through the exhaust.

 

[s351]

would running out the exhaust mess up your mufflers at all?

 

[65fastback289]

would running out the exhaust mess up your mufflers at all?

not sure, I have straight through bassani mufflers so i doubt it would make a big difference. a chambered muffler might collect a little but it should burn off.